Single-inhaler combination therapy for asthma: a review of cost effectiveness

Clinical studies have shown that the combination of an inhaled corticosteroid (ICS) and a long-acting beta(2)-adrenoceptor agonist (LABA) for patients with asthma is more effective than the use of ICS alone in equivalent or higher doses, as well as the use of other combinations. However, the relatively higher acquisition costs for the combination therapy require assessment of the value of the incremental costs, especially from a societal perspective. This review provides an overall assessment of the cost effectiveness of ICS plus LABA combination therapy for asthma. A systematic literature research was conducted in MEDLINE to identify studies published between January 1994 and September 2005. Cost-effectiveness studies derived from 11 clinical studies were identified. The ICS plus LABA combination was compared with ICS alone in eight studies, ICS plus a leukotriene antagonist in two studies, and a leukotriene antagonist alone in one study. All studies focused on measuring direct medical costs in a total of six different healthcare systems, and three studies conducted sensitivity analyses, including productivity costs. Outcomes were measured in treatment success (changes in lung function), episode-free days, and symptom-free days by evaluating short-term follow-up. The combination of ICS and LABA was found to be more efficacious and cost effective compared with ICS alone or alternative combinations of controller medications. Further considerations for measuring long-term outcomes and dose-response relationships might be required to provide further evidence on the cost effectiveness of combination therapy with ICS plus LABA.